1. Field of the Invention
The present invention relates to mycology, entomology, and the use of preconidial preparations of entomopathogenic fungi as attractants (mycoattractants) and biopesticides (mycopesticides, mycoinsecticides) in combination with other technologies to control, decrease, limit or prevent the spread of diseases carried by insects and/or other arthropods. More particularly, the invention relates to the control of zoonotic diseases by attracting, and attracting and killing insects, including ants, flies, beetles, cockroaches, bed bugs, mosquitoes, grasshoppers and other arthropods such as ticks, mites, midges, lice and fleas, using pre-sporulating mycelia of entomopathogenic fungi and extracts of pre-sporulating mycelia.
2. Description of the Related Art
Diseases emanating from ecologically distressed and polluted environments increasingly threaten animals and plants. With deforestation, habitat destruction, decline in water quality, decreases in biodiversity, all of which are exacerbated by global climate change and human impacts, zoonotic diseases are increasingly a threat to healthy environments and their inhabitants, especially animal populations, including humans and their livestock. Many of these disease-causing organisms are carried by or bred within insects or other arthropods. Insects are any of the large class (Insecta) of small arthropod animals characterized, in the adult state, by division of the body into head, thorax, and abdomen, three pairs of legs on the thorax, and, usually, two pairs of membranous wings; arthropods are any of the largest phylum (Arthropoda) of invertebrate animals with jointed legs, a segmented body, and an exoskeleton, including herein insects, arachnids such as spiders, mites and ticks, and myriapods. Since many of these bite humans and livestock, as well as damage plants, they transmit a wide variety of diseases, many of which result in billions of dollars worth of damage to economies worldwide.
Insects are among the most diverse and numerous life forms on earth. While the majority of the one million named species of insects are considered beneficial, somewhere from 1% to 5% are considered to be pests. Some of these insect pests not only cause tremendous losses in terms of direct destruction of crops, livestock, and human dwellings, they are also vectors for pathogens including protozoa, round worms, bacteria, and viruses that cause devastating human health problems. As climates change, with an overall tendency to warming, tropical and subtropical diseases are spreading into temperate regions, once devoid of these threats. The negative physical, mental, economic, social, and ecological implications of disease carrying pest insects and arthropods are difficult to quantify since their effects are wide-ranging and multidimensional. As ecosystems in which humans dwell are harmed, water is polluted, sanitation hurdles mount, toxins are accumulated, and food scarcity increases, animals (including humans) become much more susceptible to infection from pathogen-carrying insects and arthropods as their innate immune systems are weakened. Chemical pesticides, antibiotics, and vaccinations are notoriously ineffective against long-term exposure to populations of rapidly evolving organisms. Additionally, resistance to pesticides and antimicrobials can result in “super-bugs” which often develop in both insects and the microbes they transmit. As diseases ebb and flow, we need a more sophisticated way of out-smarting the vectors that carry them. If the vector can be stopped, the disease can be stopped. By using attractants from entomopathogenic fungi, this new approach allows the unusual flexibility of being able to switch or combine attractant extracts and mycelium sourced by tapping into the vast and continually evolving genome of naturally occurring wild or human-improved strains.
Many insects and arthropods are vectors for contagions. Some in particular are common carriers of pathogens and contagions. Many of these contagions are spread by simple contact, some are spread from bites or proboscis punctures, while others can be transmitted to animals when they consume these disease-laden insects.
Zoonotic disease is defined as any disease that is spread from animals to people. Any subsequent insect controlling technology can be enhanced since the insects and arthropods become concentrated as a result of the attractant properties of the preconidial mycelium or extract of selected entomopathogenic fungi. The further novelty of this invention is that it allows other technologies that limit disease to work more effectively by concentrating and localizing the disease-spreading organism to a more centralized locus, reducing expenses while enhancing efficacies. In essence, disease vectors by insects and arthropods can be better controlled.
Ants can carry diverse populations of pathogenic bacteria. For instance, Pharaoh ants (Monomorium pharaonis and related species) are known as vectors to more than dozen pathogenic bacteria, including Salmonella spp., Staphylococcus spp., and Streptococcus spp., and are especially dangerous to burn victims recovering in hospital environments. See Beatson S. H., “Pharaoh ants as pathogen vectors in hospitals,” Lancet 1: pp. 425-427(1972); Haack K. D., Granovsky T. A., Ants, In Handbook of Pest Control, Story K. and Moreland D. (eds.), Franzak & Foster Co., Cleveland, Ohio. pp. 415-479 (1990); and Smith E. H., Whitman R. C., Field Guide to Structural Pests, National Pest Management Association, Dunn Loring, Va., (1992).
Although we have identified many diseases mosquitoes carry, we are unlikely to have identified them all. More mosquito-pathogen vectors are likely to be discovered as insects (and arthropods) evolve and species populations re-mix. We know that mosquitoes can be the vector for viruses, using their proboscis as a form of a syringe capable for injecting many viruses, specifically West Nile virus, encephalitis viruses (Western equine encephalitis, St. Louis encephalitis, La Crosse encephalitis, Japanese encephalitis, Eastern equine encephalitis), Yellow Fever, and Dengue Fever. How many other viruses carried by mosquitoes, yet unknown or not yet evolved, will be discovered? Surely, there will be more.
Mosquitoes also inject protozoa into humans, including malaria (Plasmodium falciparum), which still results in millions of deaths per year worldwide. Control measures have included the use of chemical pesticides such as DDT™ and Deltamethrin™; however, their recurrent and prolonged use stimulates resistance. It seems Nature always finds a way around chemical “solutions.” To resolve complex problems in Nature, complex solutions are needed. This invention speaks directly to this issue.
Even the use of pesticide impregnated mosquito nets, which have been initially effective at reducing malaria infection, are not a long-term solution. Paradoxically a new study published in the prestigious medical journal The Lancet, indicates that human populations become more susceptible to malarial diseases by limiting their exposure to bites from mosquitoes. The research team, led by Dr. Jean-Francois Trape of the Institut de Recherche pour le Developpement in Dakar, found that malaria infection rates in certain segments of the population rose to levels higher than before the introduction of bed nets. The researchers collected specimens of Anopheles gambiae, the mosquito species responsible for transmitting malaria to humans in Africa. Between 2007 and 2010 the proportion of the insects with a genetic resistance to one type of pesticide rose from 8% to 48%. By 2010, the proportion of mosquitoes resistant to Deltamethrin, the chemical recommended by the World Health Organization for bed nets, was 37%. In the last four months of the study, the researchers found that the incidence of malaria attacks returned to high levels. Among older children and adults the rate was even higher than before the introduction of the nets. The researchers argue that the initial effectiveness of the bed nets reduced the amount of immunity that people acquire through exposure to mosquito bites. Combined with resurgence in resistant insects, there was a rapid rebound in infection rates. The authors are worried that their study has implications beyond Senegal, writing “these findings are a great concern since they support the idea that insecticide resistance might not permit a substantial decrease in malaria morbidity in many parts of Africa.” Trape, J-F. et al., “Malaria morbidity and pyrethroid resistance after the introduction of insecticide-treated bednets and artemisinin-based combination therapies: a longitudinal study,” The Lancet Infectious Diseases, early online publication, doi: 10.1016/S1473-3099(11)70194-3 (2011).
Below is a short summary of insects and arthropods with some of the zoonotic pathogens they transmit.
Insects and Arthropods Vectoring Zoonotic Pathogens
Ants: Bacteria (Salmonella spp., Staphylococcus spp., Streptococcus spp., etc.) Example: Fire ants spread several bacterial diseases in hospitals, including Staphylococcus, Salmonella and Clostridium. 
Mosquitoes: Malaria protozoa (Plasmodium falciparum) carried by 30-40 species, including Anopheles gambiae. Viruses: West Nile (carried by more than 42 species), encephalitis, Yellow Fever and Dengue Fever (carried by several species of Aedes, including A. aegypti).
Flies: Bacteria, protozoa (ex. Tsetse fly carries the protozoan Trypanosoma causing often-fatal ‘sleeping sickness’). Flies also spread viruses, including influenza strains H5N2 & H5N1 (bird flu) and H1N1 (swine flu), which can also be carried by Blow Flies (Calliphoridae, Calliphora vicina and related species) and the common house fly (Musca domestica and related species). Houseflies can also transmit typhoid (Salmonella typhi) and dysentery (a disease complex caused by viruses, bacteria, protozoa and parasitic worms). White flies can transmit begomoviruses (family Geminiviridae), criniviruses, ipomoviruses, torradoviruses, and some carlaviruses.
Bed Bugs: MRSA (methicillin resistant Staphylococcus aureus bacteria) carried by Cimex species. Other bacteria can be transmitted by bed bugs.
Lice and ticks: Bacteria: Rickettsia spp. causing Rocky Mountain Spotted fever; Bartonella vinsonii & B. henseiae causing intramuscular infections; and Borrelia burgdorferi causing Lyme disease.
Fleas: Bacteria, including Yernsia pestis causing bubonic plague.
Midges: Viruses (Blue tongue virus to cattle, epizootic hemorrhagic disease).
Leafhoppers: Tomato/Tobacco Mosaic viruses, wheat striate mosaic virus, maize fine streak virus, chickpea chlorotic dwarf virus, green petal virus, and others.
Virtually all biting insects and arthropods can result in bacterial or viral infections, either directly from a contagion reservoir within them or from wound exposure to the open environment. This is true with regard to both animal and plant diseases.
The present invention affords yet another new option for disease control: to attract but not necessarily kill mosquitoes, whilst reducing or eliminating their pathogen payloads. This option is important especially in areas where the insect populations are helpful in maintaining biological diversity of other animals that are dependent upon them for food. Removing all the insects from an ecosystem would likely result in unforeseen consequences, beyond that which is readily obvious. The food web is interconnected, and while most experts will agree that reducing disease vectors is prudent; destroying a native insect population is not.
Moreover, since Metarhizium species are natural parasites of mosquitoes, the natural genome of this and other entomopathogenic fungi offer sources of ever-evolving libraries of new strains, making resistance much more unlikely compared to chemical pesticides. An additional advantage of using preconidial entomopathogenic fungi such as Metarhizium anisopliae is that native strains of this fungus can be isolated wherever mosquitoes live, meaning that the constant co-evolution of this fungus to overcome resistance factors of the mosquitoes provides us with a unique partnership with nature to constantly adapt native, new strains of this fungus for implementation in controlling mosquitoes. Moreover, if new strains of Metarhizium anisopliae are blended with any antimicrobial agent, the insects and the diseases they spread can be further controlled. Should the disease organism being carried by, for instance, a mosquito, develop resistance to an antimicrobial or antiviral drug, then a mixture of more than one drug or remedy can be employed to overcome resistance. Thus, this invention allows for a platform for continually out-smarting resistance by blending technologies and combining antimicrobials—out-racing the ability of insects and pathogens to adapt to either the entomopathogenic fungus or the antimicrobial method employed at the points of contact. Such synergism can have many derivative improvements and are expected by this inventor.
As an example, Artemesinin from Artemesia plants, has been found to be effective against malaria. Either pure or less expensive crude, extracts containing Artemesinin can be blended with the preconidial extracts and/or mycelium of Metarhizium anisopliae. This combination would both attract mosquitoes and upon ingestion of the blended extract reduce the malarial loads they carry. Similarly, other combinations could include any or a plurality of antimalarial drugs or the crude precursors from which they are derived, including but not limited to: Quinine and related agents, Chloroquine, Amodiaquine, Pyrimethamine, Proguanil, Sulfonamides, Mefloquine, Atovaquone, Primaquine, Halofantrine, Doxycycline, and Clindamycin. Moreover, the water/ethanol extracts of some polypore mushrooms, particularly Polyporus umbellatus has shown strong antimalarial activity, although the active ingredients have not yet been identified. Lovy, A., B. Knowles, R. Labbe & L. Nolan, “Activity of edible mushrooms against the growth of human T4 leukemia cancer cells, and Plasmodium falciparum,” Journal of Herbs, Spices & Medicinal Plants vol. 6(4): 49-57 (1999). Additionally, other polypore mushrooms, and Basidiomycetes, are likely to produce antimalarial compounds.
Another example would be to blend the extracts or mycelia of preconidial entomopathogenic fungi with the less expensive antiviral drug precursors, expired antiviral drugs, or drugs such as Abacavir, Aciclovir, Acyclovir, Adefovir, Amantadine, Amprenavir, Ampligen, Arbidol, Atazanavir, Atripla, Boceprevir, Cidofovir, Combivir, Darunavir, Delavirdine, Didanosine, Docosanol, Edoxudine, Efavirenz, Emtricitabine, Enfuvirtide, Entecavir, Famciclovir, Fomivirsen, Fosamprenavir, Foscarnet, Fosfonet, Ganciclovir, Ibacitabine, Imunovir, Idoxuridine, Imiquimod, Indinavir, Inosine, Interferon type III, Interferon type II, Interferon type I, Interferon, Lamivudine, Lopinavir, Loviride, Maraviroc, Moroxydine, Methisazone, Nelfinavir, Nevirapine, Nexavir, Nucleoside analogues, Oseltamivir (Tamiflu®), Peginterferon alfa-2a, Penciclovir, Peramivir, Pleconaril, Podophyllotoxin, Protease inhibitors, Raltegravir, Reverse transcriptase inhibitors, Ribavirin, Rimantadine, Ritonavir, Pyramidine, Saquinavir, Stavudine, Tea tree oil, Tenofovir, Tenofovir disoproxil, Tipranavir, Trifluridine, Trizivir, Tromantadine, Truvada, Valaciclovir (Valtrex®), Valganciclovir, Vicriviroc, Vidarabine, Viramidine, Zalcitabine, Zanamivir (Relenza®), and Zidovudine.
This same principle could also be used to enhance more traditional insect control devices. For example, blends of extracts and preconidial mycelium of entomopathogenic fungi can be used to enhance performance of UV light based insect traps such as BASF's “Vector™” or CO2 emitting suction traps. In essence, any current or future method might well result in greater performance for controlling insects, whether these be mosquitoes, flies or others, by employing extracts and mycelium of preconidial entomopathogenic fungi.
Using preconidial entomopathogenic fungi to develop new or enhance existing insect control measures may also be used to help mitigate diseases spread by flies. Flies such as the blood sucking Tsetse fly carry the protozoan Trypanosoma that causes an often fatal “sleeping sickness” in Africa. Blow flies, aka ‘blue bottle flies’ (Calliphora nigribarbis and Aldrichina graham) and house flies (Musca domestica) have both been found by multiple researchers to harbor and carry bird flu viruses, meaning that poultry farms and slaughter houses represent nexus distribution points for this contagion. See http://www.flutrackers.com/forum/showthread.php?t=29335. According to the researchers, “more than one-third of the adult Musca domestica sampled contained AI [avian influenza] virus particles.” Blow flies swarm and breed upon carcasses, including birds, as well as broken eggs and bird feces, and can acquire bird flu viruses. The ever-so-common housefly can carry bird flu viruses, and potentially re-infect chickens and other poultry that eat flies regularly. What has not been reported yet is whether or viruses such as bird flu can be transmitted to humans from infected flies. Given the huge swarms of flies that congregate around dead and diseased animals, this vector seems likely. According to the researchers, “more than one-third of the adult Musca domestica sampled contained AI virus particles”(http://www.flutrackers.com/forum/showthread.php?t=29640).
As symptoms of bird flu infection may not be evident for a few days, and yet the animals can be infectious, factory farms, and in particular slaughter houses (where blow flies feed on cadavers and also make contact with living animals) can be a serious, although largely unpublicized threat to public health. Flies infected from contacting poultry infected from bird flu, for example, can be eaten by non-infected birds, thus increasing the probably of disease transmission. Thus the need to attract virus-vectoring flies, and to reduce their pathogen payload is dually important. Note that even if the flies are not caught, but seek out, make contact with, and/or ingest the sweet extracts having antiviral or antimicrobial properties, the benefits incurred are that these insects are then less infectious due to reduced levels of contagions.
Because the purification of antimicrobial and antiviral drugs is typically more much expensive than their crude, or semi-pure precursors, this invention anticipates that less-than-pharmaceutical grade antiviral, antimicrobial, and anti-protozoa medicines can be employed in combination with extracts and the mycelium of pre-conidial entomopathogenic fungi to create a successful treatment in the prevention, mitigation, or curing of contagions transmitted by insects and arthropods. Moreover, the inventor's prior research on the use of polypore mushroom derivatives to combat viruses, which employ a similar method of extraction to the methods described herein for the creation of attractant preconidial entomopathogenic extracts, is yet another application of this novel way of limiting zoonotic contagions.
Other insect arthropods such as lice and ticks can carry Rickettsia bacteria causing Rocky Mountain Spotted fever. Fleas can transmit bubonic plague (Yersinia pestis bacteria) and ticks can carry Lyme disease (Borrelia bacteria) to humans, deer, and other animals. ‘Bed bugs’ (Cimex species from the Cimicidae) have also recently been found to carry drug-resistant staph bacteria (MRSA—methicillin resistant Staphylococcus aureus), compounding the challenge faced by hospitals, hotels, dormitories, army barracks, prisons, and other densely populated areas. Denser populations of humans and animals—especially denser populations of immunocompromised humans and animals—increase the probably of infection and re-transmission. Whether the initial infection being transmitted from a biting insect or arthropod is from a bacterium or a virus, co-occurrence of non-insect borne diseases may more readily ensue. The now-lowered immunity of the infected animal population at large may, for instance, make the spread of Ebola, Hanta, bird flu viruses, diphtheria, dysentery, and any contagion more readily spreadable. The resultant consequences of a population's lowered immunity can also degrade the overall population's immunological defenses against cancers. Conversely, those already suffering from cancer, or have compromised immune systems due to other diseases, are more susceptible to infection.
Moreover, insects spread viruses into plants. For instance, caterpillars and grasshoppers spread the Tomato-Tobacco Mosaic Virus. For farmers, there are dual advantages for controlling plant eating insects and the crop destroying diseases they spread. By combining extracts from the polypore mushroom, Fomes fomentarius, a source of antiviral agents active against the Tobacco Mosaic Virus with extracts of preconidial mycelium of Cordyceps species (well known for infecting caterpillars and grasshoppers), farmers could benefit by both limiting these crop damaging insects and lessening the threat of viruses they spread. This is but one of many examples that will become obvious and are expected manifestations of this over-arching invention.
Hence this inventor sees a two-fold need: to control movement of insects, and to control the pathogenic bio-burden of insects and arthropods that transmit diseases to people, animals, and plants. Combining methods and compositions discussed herein to create discrete ways to attract disease-carrying insects and subsequently killing them and/or reducing their pathogenic payloads will be important for protecting environmental health. In the age of technologies creating genetically modified organisms, potentiating pathogen carrying insects as biological weapons is possible and protection from such threats is sorely needed. Hence, this invention could be important for defense against bioterrorism in its many elaborations.